Swiss Mountain Pine / Mugo pine / Dwarf mountain pine
(Pinus mugo)
Country of Origin : Central Europe
Bonsai Styles : All the bonsai styles except broom style
Zone : 3 – 7
Pinus mugo, also known as bog pine, creeping pine or mountain pine, is a hardy evergreen conifer.
Mugo Pine is very tough and easy to keep although it is not the preferred choice to make a bonsai specimen.
The wild specimens collected from the mountains, however, have the potential to grow into a superb bonsai tree.
In addition to its sturdy, compact form, this species has short branches and a gnarled trunk with scaly gray bark.
The dark green needles are borne in paired shoots (candles).
Horticulturists have developed many dwarf and slow-growing clones from this natural variety. Among the more popular named clones are:
- ‘Gnom‘ – This variety has a tight, small and spherical shaped foliage structure. The needles are short.
- ‘Mops’ – This variety has similar appearance as Gnom variety. However, it is slow growing and smaller in size.
Mugo pine bonsai can be trained in any bonsai style.
However, old and gnarled specimens look good as driftwood bonsai. And, young Pinus mugo trees are suitable for informal uprights, cascades or windswept bonsai.
Best location to keep Mugo pine Bonsai
Mugo pine bonsai can be kept in full sun through out the growing season.
These are very tough trees and can withstand harsh conditions. However it is always advisable to provide them with favorable growing conditions.
In poor conditions the tree will survive, but it will grow as a scrubby, partially flattened and twisted tree. On the other hand, in good conditions, it will become a dense, bushy large shrub or small tree suitable for bonsai.
In winter, mugo pines typically do not require special protection, although it might be worthwhile to give a costly specimen some protection if temperatures drop below 23°F (-5°C).
Also read, how to choose a bonsai pot for your bonsai.
Refer sunlight requirements for indoor plants for more indoor gardening ideas. Also, refer to do bonsai trees need sunlight for more indoor and outdoor bonsai location ideas.
Propagation of Mugo pine tree
Mugo Pine can be propagated by sowing seeds or grafting.
Mid to later winter is a good time for sowing Mugo pine seeds.
Soak fresh seeds overnight in winter. In the morning, check the seeds. Discard the seeds which float on water. Sow the seeds which remain submerged.
Keep the pot in which the seed is sown exposed to frost. However, protect it from birds and rodents.
Fresh seeds will germinate faster.
For dwarf varieties, grafting can be performed.
Watering Mugo pine Bonsai
While pines require less water than deciduous trees, they should still be watered regularly throughout the growing season, with more water in summer and less in winter.
Keep the bonsai soil moist in winter, but don’t let it dry out completely.
In the event that the soil dries out completely, the bonsai tree will not survive.
A general rule to follow while watering pine bonsai is, check the soil. If the soil feels wet to the touch do not water.
You can also spray some mist on the foliage of the bonsai tree.
Read watering bonsai tree for more details about immersion technique.
Wiring Mugo pine Bonsai
Trees like this are very flexible when it comes to wiring.
You can wire branches of Pinus mugo bonsai any time of year, except when new shoots are growing.
Make sure needles are not trapped under the wire.
It is possible to leave the wires on for up to two years, depending on the tree’s health and vigor.
Pruning Mugo pine Bonsai
When to prune Mugo pine bonsai?
How to prune Mugo pine bonsai?
Any time between spring and fall is a good time to prune away unwanted branches (long primary shoots).
Be careful not to cut through the needles when cutting just above a cluster of needles. Cut needles will end up browning and falling.
Since pines exude a resin that acts as a cut paste, there is no need for sealing after pruning.
Remove old needles and overcrowded twigs from the tree in late summer or early winter to allow winter light to enter the tree.
Pinching Mugo pine Bonsai
Once the needles lengthen in late spring, pinch out the new candles (elongating shoots) with your fingers.
Remove one or two of the strongest candles from a cluster of three or five.
Repotting Mugo pine Bonsai
When to repot Mugo pine bonsai?
IMPORTANT : Pinus mugo bonsai does not like frequent repotting. The tree does not need to be repotted as long as it appears healthy.
Pinus mugo bonsai tree can be repotted every 3-5 years in mid spring.
The bonsai tree’s root development determines how often it needs to be repotted. Keep an eye on whether the roots are pot bound.
Be careful not to tear the roots when untangling them.
Avoid lime rich soil.
You can use a free-draining, bonsai soil mix. Eg. Mix 20 percent organic matter with 80 percent grit.
OR
Use akadama with 30% grit.
OR
You can also make a soil mix of loam, sharp sand and leaf mold (or compost) in the ration of 1:1:1.
Must Read: Bonsai Soil Recipes
Must read : Choosing the right bonsai container
Feeding Mugo pine Bonsai
The feed should be given every three to four weeks.
In spring and fall or early winter, apply a general fertilizer, but do not apply it between mid- and late-summer.
In Pinus mugo bonsai, overfeeding will result in long needles and premature branch thickening. So fertilize moderately and monitor the growth.
Read more about bonsai fertilizer and its application.
Diseases and pest of Mugo pine Bonsai
It is common for pine adelgids (sap-sucking insects) to cause problems in mid- to late-spring.
The new shoots are covered with a white, waxy coating.
A white coating that the insects leave on healthy plants is unsightly, even though they don’t have an adverse effect on the bonsai trees’ vigor.
As a result of the protective coating over the shell of insects, spraying in late spring is often ineffective.
A late winter insecticide spray is the most effective treatment for overwintering nymphs.
Or you can mix a few drops of detergent and insecticide in water and spray the solution. The detergent will help in penetrating the waxy protective coating of insects and deliver the insecticide.
Mugo pine bonsai care
Pinus mugo sheds its old needles (2-3 year old) in fall, like other pines. You shouldn’t freak out when you see this; the bonsai tree is not dying. The bonsai will soon look good and healthy once the old needles have been removed by hand.
Make sure that you are not over watering the bonsai tree. Waterlogged soil will quickly result in root rot.
The pine trees are very finicky about the soil. However, they tend to live for a shorter period of time in lime rich soil. Hence avoid such soil while repotting.
There have been many illegal digs in the wild of old specimens of mugo pines. It is always advisable to obtain permission from the landowner or public authority before removing such material to make a bonsai tree.
What to look for when buying Mugo pine Bonsai
Often, wild Mugo pine bonsai trees are very old (sometimes 80 or more years). These specimens are magnificent. Thus, they come with a hefty price also.
You should look for Pinus mugo bonsai specimens with thick, gnarled trunks and masses of deadwood in the form of jins and sharis.
Mostly the tree is grown using seeds, hence the tree will have a good root structure. However, in case the tree is grafted, make sure that the graft union on the trunk is seamless or acceptable.
Check for unsightly scars on the trunk.